If you haven't already, you can download Bommer for Autodesk Fusion 360 from the Autodesk App Store by clicking here. From that page, you can select the correct operating system, click Download, and then run the downloaded installer to install the add-in.
To launch Bommer, simply launch Fusion 360 after you've completed the Bommer installation. By default, Bommer will launch automatically with Fusion 360.
Bommer is located in the Tools section of Fusion 360, where you can find Fusion's Add-Ins menu, and other tools as well. Here's what Bommer should look like in Fusion 360, right after installation but before registration: